The processing of poultry such as chickens and turkeys has become highly automated. Birds generally are conveyed suspended by their legs from shackles conveyed by overhead conveying systems along processing lines for evisceration, cut-up, and further processing. It is highly desirable to perform as many of the processing operations on the birds as possible while the birds are suspended from their shackles to minimize handling and ensure greater uniformity in the cutting and processing of the birds. Accordingly, the birds are conveyed into engagement with various processing devices while they move in series suspended from their shackles along a processing path. For example, the birds can be de-feathered, decapitated, opened, eviscerated, and cut apart while being advanced progressively through a poultry processing plant suspended from shackles of an overhead conveyor line. As a result, the labor required for processing poultry carcasses is significantly reduced while uniformity and adjustability in the sectioning of the poultry carcasses into various poultry parts is more predictable.
Chicken wings, commonly referred to as “buffalo wings” have become a popular takeout item for home consumption and as menu items in restaurants and fast food outlets. A demand has emerged for larger and meatier wings. This extra meat generally is taken from the breast and back portions of the birds. Care must be taken to insure that a precise desired quantity of meat is pulled from each breast as the wings are removed to meet the specifications of retailers and other purchasers of the wings. To ensure efficiency and proper cooking of the wings, it is important to retailers, restaurants, and others that all the wings being cooked are of substantially the same weight. Larger wings do not cook as fast as smaller wings, and thus there is a possibility that the larger wings of a batch with smaller wings will be undercooked or that the smaller wings in a batch with larger wings will be overcooked. The result is poor quality product that may have to be discarded. Accordingly, it is important that precise, equal amounts of breast meat be removed with the wings from the poultry carcass to ensure that each wing and its attached breast meat will be of a substantially equal size and weight.
To insure uniformity in the weight of chicken wings cut from birds in an automated processing plant, wing cutter machines have been developed. One example of a wing cutter is disclosed in U.S. Pat. No. 5,429,549 of Verrijp et al., and the contents of the patent are hereby incorporated by reference. In the wing cutter machine disclosed in this patent, as birds are carried sequentially through the wing cutter, the wings on one side of the birds are engaged by a first wing guide, which tends to spread the wings. This spreading of the wings dislocates the joints between the wings and shoulders of the birds and pulls a desired quantity of meat from the breasts. The birds are thereafter engaged by a first circular rotating blade, which separates the wings and the portions of breast meat from the birds. At the same time, the wings on the opposite sides of the birds are engaged by a second wing guide, which tends to spread the wings, dislocating the shoulder joints between the wings and shoulders of the bird and pulling a desired quantity of meat from the breasts. The dislocated shoulder joints are thereafter engaged by a second circular rotating blade, which separates the wings and pulled-away breast meat from the opposite sides of the bird carcasses. Thus, wings with part of the breast meat attached are cut from the moving birds to produce consistently sized and meatier chicken wings.
Other wing cutting devices are disclosed in, for example, U.S. Pat. No. 4,651,383 of van der Eerden and U.S. Pat. No. 5,569,069 of Horst et al., and the disclosures of these patents also are hereby incorporated by reference.
One way of increasing the production of a poultry processing line is to space the shackles of the overhead conveyor system closer together so that more birds per minute are conveyed past the various processing stations of the line. For example, if a standard spacing of the shackles is 12 inches, production can be increased by spacing the shackles a narrower 8 inches apart. This narrower configuration will be referred to herein as a “narrow pitch” poultry line, and the spacing in general between shackles and birds is referred to as the “pitch” of the line. While spacing the birds closer together does not interfere with equipment at some of the processing stations of the machine, it does at others. The wing cutter can be one of these stations. More particularly, as the birds traverse the wing cutter, their carcasses are pulled backward at an angle relative to vertical as the wings are spread, pulled out of the shoulder sockets, and cut away. If birds are too close together on the processing line (i.e. if the pitch is too narrow), then leading birds can impact immediately trailing birds as the leading birds are pulled backward in the wing cutter toward the trailing birds. This can cause the trailing birds to misfeed into the wing cutter, can interfere with the proper orientation of the birds and/or their wings, and can cause other problems that result in ineffective wing removal and reduced efficiency. The bird carcasses also may bang into each other as they leave the wing cutter and swing to and fro because they are being dropped from a severe angle at the downstream end of the wing cutter. Thus, the pitch of a poultry processing line may be limited by the narrowest pitch that can be accommodated efficiently by the wing cutter.
There is therefore a need for a wing cutter for an automated poultry processing line that can tolerate substantially narrower processing pitches (an 8 inch pitch as opposed to a 12 inch pitch for example) efficiently and effectively without leading birds interfering with trailing birds as the birds move through the wing cutter and with less chance of impact after the carcasses leave the wing cutter. It is to the provision of such a wing cutter and to a method of removing wings from poultry carcasses in a narrow pitch poultry processing operation that the present invention is primarily directed.